===============
LIBRARY RULES
===============
From library maintainers:
- Link the shared library (libsimpleOCCTVP.dylib/.so or simpleOCCTVP.dll) and #include src/occt_templot.h. On macOS/Linux pass -lsimpleOCCTVP plus an rpath; on Windows link simpleOCCTVP.lib and put the .dll beside the executable or on PATH.
- Every exported symbol uses the cdecl calling convention and is prefixed ot_ (operations) or occt_templot_ (lifecycle). Call occt_templot_init() once before any other function and occt_templot_shutdown() once at exit.
- OTShapeRef, OTViewerRef, OTCameraRef, and OTDrawerRef are opaque void* handles owned by the caller. Free each with its destructor: ot_shape_free, ot_viewer_destroy, ot_camera_destroy, ot_drawer_destroy. All destructors are NULL-safe.
- Returned structs OTMeshData and OTEdgeMeshData own heap buffers; release them with ot_mesh_free / ot_edge_mesh_free. Importers and healing functions return NULL on failure; read occt_templot_last_error() (thread-local) for the reason.
- Offscreen rendering: create a viewer with ot_viewer_create(w,h), add shapes via ot_viewer_add_shape (returns a display id >0), then render with ot_viewer_render, ot_viewer_render_to_buffer, or ot_viewer_save_image. The viewer does not own the shapes.
- Set render quality with the CADRays-style knobs over OCCT Graphic3d_RenderingParams: ot_viewer_set_render_preset (DRAFT/BALANCED/PHOTOREALISTIC), ot_viewer_set_rendering_method, ot_viewer_set_path_tracing, and ot_viewer_set_shape_pbr_material.
- Document only the real exported functions declared in src/occt_templot.h; the Pascal binding pascal/occt_templot.pas mirrors them one-to-one with cdecl external declarations and adds helpers OTGetLastError, OTShapeTypeName, and OTViewerRenderToBitmap.

### C/C++ Example: Import, Mesh, and Render Shape

Source: https://github.com/secondmouseau/simpleocctvp/blob/main/README.md

Demonstrates initializing the library, importing a STEP file, getting its bounding box, extracting a triangle mesh, and rendering it to an image.

```c
#include "occt_templot.h"

int main() {
    occt_templot_init();

    // Import a STEP file
    OTShapeRef shape = ot_import_step("model.step");
    if (!shape) {
        printf("Error: %s\n", occt_templot_last_error());
        return 1;
    }

    // Get bounding box
    double xmin, ymin, zmin, xmax, ymax, zmax;
    ot_shape_bounding_box(shape, &xmin, &ymin, &zmin, &xmax, &ymax, &zmax);

    // Extract triangle mesh
    OTMeshData mesh = ot_mesh_shape(shape, 0.1);
    printf("Triangles: %d, Vertices: %d\n", mesh.triangle_count, mesh.vertex_count);
    ot_mesh_free(&mesh);

    // Offscreen render to PNG
    OTViewerRef viewer = ot_viewer_create(800, 600);
    ot_viewer_add_shape(viewer, shape, OT_DISPLAY_SHADED);
    ot_viewer_fit_all(viewer);
    ot_viewer_save_image(viewer, "render.png");
    ot_viewer_destroy(viewer);

    ot_shape_free(shape);
    occt_templot_shutdown();
    return 0;
}
```

--------------------------------

### Runnable Example

Source: https://github.com/secondmouseau/simpleocctvp/blob/main/docs/reference/c-api.md

A complete example demonstrating importing a STEP file, checking its type, exporting it as STL, and cleaning up resources.

```APIDOC
## Runnable Example — import, inspect, re-export

```c
#include "occt_templot.h"
#include <stdio.h>

int main(void) {
    occt_templot_init();

    OTShapeRef shape = ot_import_step("model.step");
    if (!shape) {
        printf("import failed: %s\n", occt_templot_last_error());
        occt_templot_shutdown();
        return 1;
    }

    printf("shape type code: %d\n", ot_shape_type(shape));

    if (!ot_export_stl(shape, "model.stl", 0.1))
        printf("export failed: %s\n", occt_templot_last_error());

    ot_shape_free(shape);
    occt_templot_shutdown();
    return 0;
}
```
```

--------------------------------

### Offscreen Render to PNG Example

Source: https://github.com/secondmouseau/simpleocctvp/blob/main/docs/reference/c-api.md

Demonstrates how to initialize the library, load a STEP model, set up a viewer with specific rendering parameters, and save the rendered output as a PNG image. This example performs an offscreen render without displaying a window.

```c
#include "occt_templot.h"
#include <stdio.h>

int main(void) {
    occt_templot_init();

    OTShapeRef shape = ot_import_step("model.step");
    if (!shape) { occt_templot_shutdown(); return 1; }

    OTViewerRef viewer = ot_viewer_create(800, 600);
    int32_t id = ot_viewer_add_shape(viewer, shape, OT_DISPLAY_SHADED);

    ot_viewer_set_shape_material(viewer, id, "steel");
    ot_viewer_set_background_gradient(viewer, 0.2,0.2,0.3, 0.0,0.0,0.0);
    ot_viewer_set_render_preset(viewer, OT_PRESET_BALANCED);
    ot_viewer_set_view_orientation(viewer, OT_VIEW_ISO);
    ot_viewer_fit_all(viewer);

    if (!ot_viewer_save_image(viewer, "render.png"))
        printf("render failed: %s\n", occt_templot_last_error());

    ot_viewer_destroy(viewer);
    ot_shape_free(shape);
    occt_templot_shutdown();
    return 0;
}
```

--------------------------------

### Example Usage

Source: https://github.com/secondmouseau/simpleocctvp/blob/main/docs/reference/c-api.md

A basic example demonstrating the initialization, version retrieval, error checking, and shutdown of the library.

```APIDOC
```c
#include "occt_templot.h"
#include <stdio.h>

int main(void) {
    occt_templot_init();
    printf("simpleOCCTVP %s\n", occt_templot_version());
    if (occt_templot_last_error())
        printf("error: %s\n", occt_templot_last_error());
    occt_templot_shutdown();
    return 0;
}
```
```

--------------------------------

### Pascal Binding Example: Load Mesh and Render

Source: https://github.com/secondmouseau/simpleocctvp/blob/main/docs/reference/c-api.md

An example demonstrating how to use the Free Pascal binding to load a STEP model, extract mesh data, and render it to a bitmap.

```pascal
uses occt_templot;

procedure LoadMeshAndRender;
var
  shape: OTShapeRef;
  mesh: OTMeshData;
  viewer: OTViewerRef;
begin
  occt_templot_init;
  try
    shape := ot_import_step('model.step');
    if shape = nil then
      raise Exception.Create('import failed: ' + OTGetLastError)
    else
      try
        mesh := ot_mesh_shape(shape, 0.1);
        try
          WriteLn('triangles: ', mesh.triangle_count);
        finally
          ot_mesh_free(mesh);
        end;

        viewer := ot_viewer_create(800, 600);
        try
          ot_viewer_add_shape(viewer, shape, OT_DISPLAY_SHADED);
          ot_viewer_set_render_preset(viewer, OT_PRESET_BALANCED);
          ot_viewer_fit_all(viewer);
          ot_viewer_save_image(viewer, 'render.png');
        finally
          ot_viewer_destroy(viewer);
        end;
      finally
        ot_shape_free(shape);
      end;
  finally
    occt_templot_shutdown;
  end;
end;
```

--------------------------------

### Runnable Example: Import, Inspect, Re-export (C)

Source: https://github.com/secondmouseau/simpleocctvp/blob/main/docs/reference/c-api.md

Demonstrates importing a STEP file, checking its type, exporting it to STL, and cleaning up resources.

```c
#include "occt_templot.h"
#include <stdio.h>

int main(void) {
    occt_templot_init();

    OTShapeRef shape = ot_import_step("model.step");
    if (!shape) {
        printf("import failed: %s\n", occt_templot_last_error());
        occt_templot_shutdown();
        return 1;
    }

    printf("shape type code: %d\n", ot_shape_type(shape));

    if (!ot_export_stl(shape, "model.stl", 0.1))
        printf("export failed: %s\n", occt_templot_last_error());

    ot_shape_free(shape);
    occt_templot_shutdown();
    return 0;
}
```

--------------------------------

### Dynamic Loading C Example (Unix)

Source: https://github.com/secondmouseau/simpleocctvp/blob/main/README.md

Loads the SimpleOCCTVP library at runtime using dlopen and retrieves the initialization function.

```c
// Unix (macOS / Linux)
#include <dlfcn.h>
void *lib = dlopen("libsimpleOCCTVP.dylib", RTLD_NOW);  // or .so
void (*init)(void) = dlsym(lib, "occt_templot_init");
init();
// ...
dlclose(lib);
```

--------------------------------

### Dynamic Loading C Example (Windows)

Source: https://github.com/secondmouseau/simpleocctvp/blob/main/README.md

Loads the SimpleOCCTVP library at runtime using LoadLibraryA and retrieves the initialization function.

```c
// Windows
#include <windows.h>
HMODULE lib = LoadLibraryA("simpleOCCTVP.dll");
void (*init)(void) = (void(*)(void))GetProcAddress(lib, "occt_templot_init");
init();
// ...
FreeLibrary(lib);
```

--------------------------------

### Runnable example — extract and free a mesh

Source: https://github.com/secondmouseau/simpleocctvp/blob/main/docs/reference/c-api.md

A complete C code example demonstrating how to initialize the library, import a STEP model, extract its mesh data using `ot_mesh_shape`, print basic mesh information, free the mesh data using `ot_mesh_free`, free the shape, and shut down the library.

```APIDOC
## Runnable example — extract and free a mesh

```c
#include "occt_templot.h"
#include <stdio.h>

int main(void) {
    occt_templot_init();

    OTShapeRef shape = ot_import_step("model.step");
    if (!shape) { occt_templot_shutdown(); return 1; }

    OTMeshData mesh = ot_mesh_shape(shape, 0.1);
    if (mesh.vertex_count > 0) {
        printf("vertices: %d  triangles: %d\n",
               mesh.vertex_count, mesh.triangle_count);
        /* mesh.vertices is [x,y,z, nx,ny,nz, ...] — 6 floats per vertex */
        float x = mesh.vertices[0], y = mesh.vertices[1], z = mesh.vertices[2];
        printf("first vertex: %.3f %.3f %.3f\n", x, y, z);
    }
    ot_mesh_free(&mesh);   /* always free; safe on a zeroed struct */

    ot_shape_free(shape);
    occt_templot_shutdown();
    return 0;
}
```
```

--------------------------------

### Install Linux Dependencies

Source: https://github.com/secondmouseau/simpleocctvp/blob/main/README.md

Installs necessary development libraries on Debian-based Linux systems for building and running OpenGL-dependent applications.

```bash
sudo apt-get install -y libgl-dev libglu1-mesa-dev libegl-dev libx11-dev libxi-dev libxmu-dev
```

--------------------------------

### Pascal/Lazarus Example: Load, Mesh, and Free Shape

Source: https://github.com/secondmouseau/simpleocctvp/blob/main/README.md

Demonstrates initializing the library, importing a STEP file, extracting mesh data, and freeing resources in Pascal.

```pascal
uses occt_templot;

procedure LoadAndRender;
var
  shape: OTShapeRef;
  mesh: OTMeshData;
begin
  occt_templot_init;
  try
    shape := ot_import_step('model.step');
    if shape = nil then
      raise Exception.Create('Import failed: ' + OTGetLastError);
    try
      mesh := ot_mesh_shape(shape, 0.1);
      try
        WriteLn('Triangles: ', mesh.triangle_count);
      finally
        ot_mesh_free(mesh);
      end;
    finally
      ot_shape_free(shape);
    end;
  finally
    occt_templot_shutdown;
  end;
end;
```

--------------------------------

### Main Program Entry with C API Usage

Source: https://github.com/secondmouseau/simpleocctvp/blob/main/docs/reference/c-api.md

A basic example demonstrating the initialization, version retrieval, error checking, and shutdown sequence of the simpleOCCTVP C API.

```c
#include "occt_templot.h"
#include <stdio.h>

int main(void) {
    occt_templot_init();
    printf("simpleOCCTVP %s\n", occt_templot_version());
    if (occt_templot_last_error())
        printf("error: %s\n", occt_templot_last_error());
    occt_templot_shutdown();
    return 0;
}
```

--------------------------------

### Runnable Example: Analyze, Heal, and Measure Shape

Source: https://github.com/secondmouseau/simpleocctvp/blob/main/docs/reference/c-api.md

Demonstrates a typical workflow: importing a STEP file, analyzing its quality, healing it, measuring its volume and bounding box, and freeing the shape resources. Includes necessary initializations and shutdowns.

```c
#include "occt_templot.h"
#include <stdio.h>

int main(void) {
    occt_templot_init();

    OTShapeRef raw = ot_import_step("imperfect.step");
    if (!raw) { occt_templot_shutdown(); return 1; }

    OTShapeAnalysis a = ot_analyze_shape(raw, 1e-6);
    printf("free edges: %d  gaps: %d  valid: %d\n",
           a.free_edge_count, a.gap_count, a.is_valid);

    OTShapeRef healed = ot_heal_shape(raw);
    if (healed) {
        double xmin, ymin, zmin, xmax, ymax, zmax;
        ot_shape_bounding_box(healed, &xmin, &ymin, &zmin, &xmax, &ymax, &zmax);
        printf("volume: %.3f  bbox: [%.1f..%.1f]\n",
               ot_shape_volume(healed), xmin, xmax);
        ot_shape_free(healed);
    }

    ot_shape_free(raw);
    occt_templot_shutdown();
    return 0;
}
```

--------------------------------

### Runnable example: Extract and free a mesh

Source: https://github.com/secondmouseau/simpleocctvp/blob/main/docs/reference/c-api.md

Demonstrates the process of initializing the library, importing a STEP model, extracting its mesh data using `ot_mesh_shape`, printing vertex and triangle counts, accessing the first vertex's coordinates, and finally freeing the mesh data and shape.

```c
#include "occt_templot.h"
#include <stdio.h>

int main(void) {
    occt_templot_init();

    OTShapeRef shape = ot_import_step("model.step");
    if (!shape) { occt_templot_shutdown(); return 1; }

    OTMeshData mesh = ot_mesh_shape(shape, 0.1);
    if (mesh.vertex_count > 0) {
        printf("vertices: %d  triangles: %d\n",
               mesh.vertex_count, mesh.triangle_count);
        float x = mesh.vertices[0], y = mesh.vertices[1], z = mesh.vertices[2];
        printf("first vertex: %.3f %.3f %.3f\n", x, y, z);
    }
    ot_mesh_free(&mesh);

    ot_shape_free(shape);
    occt_templot_shutdown();
    return 0;
}
```

--------------------------------

### Get Library Version

Source: https://github.com/secondmouseau/simpleocctvp/blob/main/README.md

Retrieves the version string of the SimpleOCCTVP library. The format is typically 'major.minor.patch'.

```c
occt_templot_version();
```

--------------------------------

### Viewer Lifecycle

Source: https://github.com/secondmouseau/simpleocctvp/blob/main/docs/reference/c-api.md

Functions to create, destroy, resize, and get the dimensions of the offscreen viewer.

```APIDOC
## Viewer Lifecycle

### `ot_viewer_create`

Creates a new offscreen viewer with the specified dimensions.

**Parameters**
- `width` (int32_t) - The width of the viewer.
- `height` (int32_t) - The height of the viewer.

**Returns**
- `OTViewerRef` - A reference to the created viewer, or a null reference on failure.

### `ot_viewer_destroy`

Destroys the offscreen viewer and releases associated resources.

**Parameters**
- `viewer` (OTViewerRef) - The viewer to destroy.

### `ot_viewer_resize`

Resizes the offscreen viewer to the specified dimensions.

**Parameters**
- `viewer` (OTViewerRef) - The viewer to resize.
- `width` (int32_t) - The new width of the viewer.
- `height` (int32_t) - The new height of the viewer.

**Returns**
- `bool` - `true` if the resize was successful, `false` otherwise.

### `ot_viewer_get_size`

Retrieves the current dimensions of the offscreen viewer.

**Parameters**
- `viewer` (OTViewerRef) - The viewer to query.
- `out_width` (int32_t*) - Pointer to store the width.
- `out_height` (int32_t*) - Pointer to store the height.
```

--------------------------------

### Get simpleOCCTVP Library Version

Source: https://github.com/secondmouseau/simpleocctvp/blob/main/docs/reference/c-api.md

Retrieves the library version string. The returned pointer is owned by the library and should not be freed.

```c
const char* occt_templot_version(void);
```

--------------------------------

### Drawer Tessellation Quality Settings

Source: https://github.com/secondmouseau/simpleocctvp/blob/main/docs/reference/c-api.md

Functions to set and get tessellation quality parameters for a drawer, including deviation coefficient, angle, and maximum deviation.

```c
void   ot_drawer_set_deviation_coefficient(OTDrawerRef drawer, double coeff);
double ot_drawer_get_deviation_coefficient(OTDrawerRef drawer);
void   ot_drawer_set_deviation_angle(OTDrawerRef drawer, double radians);
double ot_drawer_get_deviation_angle(OTDrawerRef drawer);
void   ot_drawer_set_max_deviation(OTDrawerRef drawer, double deviation);
double ot_drawer_get_max_deviation(OTDrawerRef drawer);
```

--------------------------------

### Two-phase mesh extraction with separate buffers

Source: https://github.com/secondmouseau/simpleocctvp/blob/main/docs/reference/c-api.md

A two-phase API for mesh extraction where the caller manages memory. First, get counts using `ot_mesh_shape_separate`, allocate memory for vertices, normals, and indices, then fill the buffers with `ot_mesh_shape_fill`.

```c
bool ot_mesh_shape_separate(OTShapeRef shape, double deflection,
        int32_t* out_vertex_count, int32_t* out_triangle_count);
bool ot_mesh_shape_fill(OTShapeRef shape,
        float* out_vertices, float* out_normals, int32_t* out_indices);
```

--------------------------------

### Separate (caller-managed) buffers API

Source: https://github.com/secondmouseau/simpleocctvp/blob/main/docs/reference/c-api.md

A two-phase API for callers who need to manage their own memory. First, call `ot_mesh_shape_separate` to get the vertex and triangle counts. Then, allocate memory for `out_vertices`, `out_normals` (as `float[vertex_count * 3]`), and `out_indices` (as `int32_t[triangle_count * 3]`). Finally, call `ot_mesh_shape_fill` to populate these allocated buffers.

```APIDOC
## Separate (caller-managed) buffers

### Description
Two-phase API for callers that want to own the memory: first call `ot_mesh_shape_separate` to obtain counts, allocate `out_vertices`/`out_normals` as `float[vertex_count * 3]` and `out_indices` as `int32_t[triangle_count * 3]`, then call `ot_mesh_shape_fill` on the same shape.

### Function Signatures
```c
bool ot_mesh_shape_separate(OTShapeRef shape, double deflection,
        int32_t* out_vertex_count, int32_t* out_triangle_count);
bool ot_mesh_shape_fill(OTShapeRef shape,
        float* out_vertices, float* out_normals, int32_t* out_indices);
```
```

--------------------------------

### Build SimpleOCCTVP from Source

Source: https://github.com/secondmouseau/simpleocctvp/blob/main/README.md

Steps to clone the repository, build dependencies, and compile the library using CMake.

```bash
git clone https://github.com/gsdali/simpleOCCTVP.git
cd simpleOCCTVP
scripts/build-occt-deps.sh          # ~15-30 min, builds OCCT 8.0.0
cmake -B build -DCMAKE_BUILD_TYPE=Release
cmake --build build
```

--------------------------------

### Get Shape Type (C)

Source: https://github.com/secondmouseau/simpleocctvp/blob/main/docs/reference/c-api.md

Returns the type of the shape. Returns -1 for an error.

```c
int32_t ot_shape_type(OTShapeRef shape);
```

--------------------------------

### Initialize, Load, Mesh, Render, and Shutdown

Source: https://github.com/secondmouseau/simpleocctvp/blob/main/docs/guides/getting-started.md

This C code demonstrates the core workflow: initializing the library, loading a STEP file, extracting a triangle mesh, rendering the shape to a PNG image, and finally shutting down the library. Ensure proper error checking after import operations and remember to free all allocated resources.

```c
#include "occt_templot.h"
#include <stdio.h>

int main(void) {
    /* 1. Initialize once at startup. */
    occt_templot_init();

    /* 2. Load a shape. Returns NULL on failure. */
    OTShapeRef shape = ot_import_step("model.step");
    if (!shape) {
        printf("import failed: %s\n", occt_templot_last_error());
        occt_templot_shutdown();
        return 1;
    }

    double xmin, ymin, zmin, xmax, ymax, zmax;
    ot_shape_bounding_box(shape, &xmin, &ymin, &zmin, &xmax, &ymax, &zmax);
    printf("bbox x: %.2f .. %.2f\n", xmin, xmax);

    /* 3. Extract a triangle mesh (interleaved position+normal). */
    OTMeshData mesh = ot_mesh_shape(shape, 0.1);
    printf("triangles: %d  vertices: %d\n",
           mesh.triangle_count, mesh.vertex_count);
    ot_mesh_free(&mesh);            /* free the mesh buffers */

    /* 4. Render the shape offscreen and save a PNG. */
    OTViewerRef viewer = ot_viewer_create(800, 600);
    int32_t id = ot_viewer_add_shape(viewer, shape, OT_DISPLAY_SHADED);
    ot_viewer_set_shape_material(viewer, id, "steel");
    ot_viewer_set_render_preset(viewer, OT_PRESET_BALANCED);
    ot_viewer_set_view_orientation(viewer, OT_VIEW_ISO);
    ot_viewer_fit_all(viewer);
    if (!ot_viewer_save_image(viewer, "render.png"))
        printf("render failed: %s\n", occt_templot_last_error());
    ot_viewer_destroy(viewer);     /* destroy the viewer */

    /* 5. Free the shape and shut down. */
    ot_shape_free(shape);          /* the viewer does not own the shape */
    occt_templot_shutdown();
    return 0;
}

```

--------------------------------

### Camera Position and Orientation

Source: https://github.com/secondmouseau/simpleocctvp/blob/main/docs/reference/c-api.md

Functions to set and get the eye position, look-at center, and up vector of the camera.

```APIDOC
## Camera Position and Orientation

### Description
Manages the camera's position in the world, the point it is looking at, and its orientation.

### `ot_camera_set_eye`

#### Parameters
- `camera` (OTCameraRef): The camera object.
- `x`, `y`, `z` (double): The world coordinates of the camera's eye position.

### `ot_camera_get_eye`

#### Parameters
- `camera` (OTCameraRef): The camera object.
- `x`, `y`, `z` (double*): Pointers to store the camera's eye position coordinates.

### `ot_camera_set_center`

#### Parameters
- `camera` (OTCameraRef): The camera object.
- `x`, `y`, `z` (double): The world coordinates of the point the camera is looking at.

### `ot_camera_get_center`

#### Parameters
- `camera` (OTCameraRef): The camera object.
- `x`, `y`, `z` (double*): Pointers to store the look-at center coordinates.

### `ot_camera_set_up`

#### Parameters
- `camera` (OTCameraRef): The camera object.
- `x`, `y`, `z` (double): The components of the camera's up vector.

### `ot_camera_get_up`

#### Parameters
- `camera` (OTCameraRef): The camera object.
- `x`, `y`, `z` (double*): Pointers to store the camera's up vector components.
```

--------------------------------

### Get Last Error Message

Source: https://github.com/secondmouseau/simpleocctvp/blob/main/README.md

Retrieves the last error message associated with the current thread. Returns NULL if no error has occurred.

```c
occt_templot_last_error();
```

--------------------------------

### Initialize the Library

Source: https://github.com/secondmouseau/simpleocctvp/blob/main/README.md

Initializes the SimpleOCCTVP library. This function should be called once at the beginning of your application's execution.

```c
occt_templot_init();
```

--------------------------------

### Import STEP File (C)

Source: https://github.com/secondmouseau/simpleocctvp/blob/main/docs/reference/c-api.md

Imports a STEP file. Returns a new OTShapeRef or NULL on failure.

```c
OTShapeRef ot_import_step(const char* path);
```

--------------------------------

### Get Shape Bounding Box

Source: https://github.com/secondmouseau/simpleocctvp/blob/main/README.md

Retrieves the axis-aligned bounding box for a shape. Requires the shape handle and output parameters for the box coordinates.

```c
ot_shape_bounding_box(shape, ...);
```

--------------------------------

### CMake Integration: Adding from Source

Source: https://github.com/secondmouseau/simpleocctvp/blob/main/README.md

Configures CMake to add SimpleOCCTVP as a subdirectory, assuming it's built from source.

```cmake
add_subdirectory(simpleOCCTVP)
target_link_libraries(your_target PRIVATE simpleOCCTVP)
```

--------------------------------

### Run Tests

Source: https://github.com/secondmouseau/simpleocctvp/blob/main/README.md

Executes the test suite after building the library. Use --output-on-failure for detailed test results.

```bash
cd build && ctest --output-on-failure
```

--------------------------------

### Import STEP Robustly (C)

Source: https://github.com/secondmouseau/simpleocctvp/blob/main/docs/reference/c-api.md

Imports a STEP file with automatic healing and precision handling. Returns a new OTShapeRef or NULL on failure.

```c
OTShapeRef ot_import_step_robust(const char* path);
```

--------------------------------

### Define OTEdgeMeshData structure

Source: https://github.com/secondmouseau/simpleocctvp/blob/main/docs/reference/c-api.md

Defines the structure for holding edge mesh data, including vertices, vertex count, segment start indices, and segment count. Vertices are stored as simple [x,y,z] coordinates.

```c
typedef struct {
    float*   vertices;
    int32_t  vertex_count;
    int32_t* segment_starts;
    int32_t  segment_count;
} OTEdgeMeshData;
```

--------------------------------

### Create Offscreen Viewer

Source: https://github.com/secondmouseau/simpleocctvp/blob/main/README.md

Creates an offscreen viewer instance with specified width and height. Returns a reference to the viewer.

```c
ot_viewer_create(w, h);
```

--------------------------------

### Import STEP with Diagnostics (C)

Source: https://github.com/secondmouseau/simpleocctvp/blob/main/docs/reference/c-api.md

Imports a STEP file and reports on the repair steps applied. The returned shape must be freed.

```c
typedef struct {
    OTShapeRef shape;
    int32_t original_type;
    int32_t result_type;
    bool sewing_applied;
    bool solid_created;
    bool healing_applied;
} OTImportResult;

OTImportResult ot_import_step_with_diagnostics(const char* path);
```

--------------------------------

### Run Tests with xvfb on Linux

Source: https://github.com/secondmouseau/simpleocctvp/blob/main/README.md

Runs tests on headless Linux systems using xvfb to simulate a display environment for OpenGL tests.

```bash
cd build && xvfb-run ctest --output-on-failure
```

--------------------------------

### CMake Integration: Using Prebuilt Shared Library

Source: https://github.com/secondmouseau/simpleocctvp/blob/main/README.md

Configures CMake to find and use a prebuilt SimpleOCCTVP shared library, setting its location and include directories.

```cmake
# Find the prebuilt shared library
add_library(simpleOCCTVP SHARED IMPORTED)
set_target_properties(simpleOCCTVP PROPERTIES
    IMPORTED_LOCATION "${CMAKE_SOURCE_DIR}/libs/libsimpleOCCTVP${CMAKE_SHARED_LIBRARY_SUFFIX}"
    INTERFACE_INCLUDE_DIRECTORIES "${CMAKE_SOURCE_DIR}/include"
)
# On Windows, also set IMPORTED_IMPLIB to the .lib file

target_link_libraries(your_target PRIVATE simpleOCCTVP)
```

--------------------------------

### Import OBJ File (C)

Source: https://github.com/secondmouseau/simpleocctvp/blob/main/docs/reference/c-api.md

Imports an OBJ file. Returns a new OTShapeRef or NULL on failure.

```c
OTShapeRef ot_import_obj(const char* path);
```

--------------------------------

### Import STL Robustly (C)

Source: https://github.com/secondmouseau/simpleocctvp/blob/main/docs/reference/c-api.md

Imports an STL file with a sew, solid, and heal pipeline. A sewing tolerance must be provided.

```c
OTShapeRef ot_import_stl_robust(const char* path, double sewing_tolerance);
```

--------------------------------

### Viewer Lifecycle

Source: https://github.com/secondmouseau/simpleocctvp/blob/main/docs/reference/c-api.md

Functions to create, destroy, and resize the offscreen viewer.

```c
OTViewerRef ot_viewer_create(int32_t width, int32_t height);
void        ot_viewer_destroy(OTViewerRef viewer);
bool        ot_viewer_resize(OTViewerRef viewer, int32_t width, int32_t height);
void        ot_viewer_get_size(OTViewerRef viewer, int32_t* out_width, int32_t* out_height);
```

--------------------------------

### Build the Library with CMake

Source: https://github.com/secondmouseau/simpleocctvp/blob/main/README.md

Configures and builds the library using CMake. Specify the build type, e.g., Release.

```bash
cmake -B build -DCMAKE_BUILD_TYPE=Release
cmake --build build
```

--------------------------------

### Import STL File (C)

Source: https://github.com/secondmouseau/simpleocctvp/blob/main/docs/reference/c-api.md

Imports an STL file. Returns a new OTShapeRef or NULL on failure.

```c
OTShapeRef ot_import_stl(const char* path);
```

--------------------------------

### Compile C/C++ Application on Linux

Source: https://github.com/secondmouseau/simpleocctvp/blob/main/README.md

Command to compile a C application, linking against the SimpleOCCTVP library and specifying include and library paths with rpath.

```bash
cc -o myapp myapp.c -I./include -L./libs -lsimpleOCCTVP -Wl,-rpath,'$ORIGIN/libs'
```

--------------------------------

### Import with Diagnostics

Source: https://github.com/secondmouseau/simpleocctvp/blob/main/docs/reference/c-api.md

Import a STEP file and report diagnostic information about the repair process.

```APIDOC
## `ot_import_step_with_diagnostics`

### Description
Import a STEP file and report which repair steps ran. The `shape` field is owned by the caller and must be freed with `ot_shape_free` when non-`NULL`.

### Result Structure
```c
typedef struct {
    OTShapeRef shape;       /* Result shape (NULL on failure) */
    int32_t original_type;  /* TopAbs_ShapeEnum before processing */
    int32_t result_type;    /* TopAbs_ShapeEnum after processing */
    bool sewing_applied;    /* Whether sewing was needed */
    bool solid_created;     /* Whether a solid was created from a shell */
    bool healing_applied;   /* Whether healing was applied */
} OTImportResult;
```

### Signature
```c
OTImportResult ot_import_step_with_diagnostics(const char* path);
```
```

--------------------------------

### Library Initialization and Shutdown

Source: https://github.com/secondmouseau/simpleocctvp/blob/main/docs/reference/c-api.md

Functions to initialize the library before use and shut it down to release resources.

```APIDOC
## `occt_templot_init`

### Description
Initialize the library. Call once before any other function.

### Signature
```c
void occt_templot_init(void);
```
```

```APIDOC
## `occt_templot_shutdown`

### Description
Shut down the library and release global resources.

### Signature
```c
void occt_templot_shutdown(void);
```
```

--------------------------------

### Import IGES File (C)

Source: https://github.com/secondmouseau/simpleocctvp/blob/main/docs/reference/c-api.md

Imports an IGES file. Returns a new OTShapeRef or NULL on failure.

```c
OTShapeRef ot_import_iges(const char* path);
```

--------------------------------

### Import OBJ File

Source: https://github.com/secondmouseau/simpleocctvp/blob/main/README.md

Imports a shape from an OBJ file. The path to the OBJ file is required.

```c
ot_import_obj(path);
```

--------------------------------

### Build OCCT Dependencies

Source: https://github.com/secondmouseau/simpleocctvp/blob/main/README.md

Downloads and builds OCCT 8.0.0 as static libraries. Ensure you have CMake 3.20+ and a C++17 compiler.

```bash
scripts/build-occt-deps.sh
```

--------------------------------

### Render Scene to Buffer or File

Source: https://github.com/secondmouseau/simpleocctvp/blob/main/docs/reference/c-api.md

Functions to render the scene. `ot_viewer_render` returns RGBA pixels bottom-to-top and the pointer is owned by the viewer. `ot_viewer_render_to_buffer` renders into a caller-allocated buffer top-to-bottom. `ot_viewer_save_image` renders and saves to a file.

```c
const uint8_t* ot_viewer_render(
        OTViewerRef viewer,
        int32_t* out_width, int32_t* out_height, int32_t* out_size);
bool        ot_viewer_render_to_buffer(OTViewerRef viewer, uint8_t* buffer, int32_t buffer_size);
bool        ot_viewer_save_image(OTViewerRef viewer, const char* path);
```

--------------------------------

### Compile C/C++ Application on macOS

Source: https://github.com/secondmouseau/simpleocctvp/blob/main/README.md

Command to compile a C application, linking against the SimpleOCCTVP library and specifying include and library paths.

```bash
cc -o myapp myapp.c -I./include -L./libs -lsimpleOCCTVP -Wl,-rpath,@executable_path/libs
```

--------------------------------

### Import STEP File

Source: https://github.com/secondmouseau/simpleocctvp/blob/main/README.md

Imports a shape from a STEP file. The path parameter specifies the file location.

```c
ot_import_step(path);
```

--------------------------------

### Set Viewer Background Gradient

Source: https://github.com/secondmouseau/simpleocctvp/blob/main/README.md

Sets a color gradient as the background for the viewer. Requires parameters defining the gradient.

```c
ot_viewer_set_background_gradient(viewer, ...);
```

--------------------------------

### Lifecycle Functions

Source: https://github.com/secondmouseau/simpleocctvp/blob/main/README.md

Functions for initializing, shutting down, and retrieving the version and last error of the library.

```APIDOC
## Lifecycle Functions

### Description
Functions for initializing, shutting down, and retrieving the version and last error of the library.

### Functions

- **occt_templot_init()**
  - Description: Initialize the library. Call once at startup.

- **occt_templot_shutdown()**
  - Description: Release global resources. Call at exit.

- **occt_templot_version()**
  - Description: Returns version string (e.g. "0.1.0").

- **occt_templot_last_error()**
  - Description: Thread-local error message, or `NULL`.
```

--------------------------------

### Viewer Rendering Control Functions

Source: https://github.com/secondmouseau/simpleocctvp/blob/main/docs/reference/c-api.md

Provides C functions to configure various rendering parameters for the viewer, including presets, methods, path tracing, sampling, depth, shadows, reflections, antialiasing, tone mapping, depth of field, shading models, and environment cubemaps.

```c
void ot_viewer_set_render_preset(OTViewerRef viewer, OTRenderPreset preset);
void ot_viewer_set_rendering_method(OTViewerRef viewer, OTRenderingMethod method);
void ot_viewer_set_path_tracing(OTViewerRef viewer, bool enabled);
void ot_viewer_set_samples_per_pixel(OTViewerRef viewer, int32_t spp);
void ot_viewer_set_ray_depth(OTViewerRef viewer, int32_t depth);
void ot_viewer_set_shadows(OTViewerRef viewer, bool enabled, bool transparent_shadows);
void ot_viewer_set_reflections(OTViewerRef viewer, bool enabled);
void ot_viewer_set_antialiasing(OTViewerRef viewer, bool enabled);
void ot_viewer_set_tone_mapping(OTViewerRef viewer,
        OTToneMappingMethod method, double exposure, double white_point);
void ot_viewer_set_depth_of_field(OTViewerRef viewer,
        double aperture_radius, double focal_distance);
void ot_viewer_set_shading_model(OTViewerRef viewer, OTShadingModel model);
bool ot_viewer_set_environment_cubemap(OTViewerRef viewer, const char* image_path);
void ot_viewer_clear_environment_cubemap(OTViewerRef viewer);
void ot_viewer_set_environment_background(OTViewerRef viewer, bool enabled);
```

--------------------------------

### Compile C/C++ Application on Windows (MSVC)

Source: https://github.com/secondmouseau/simpleocctvp/blob/main/README.md

Command to compile a C application using MSVC, specifying include and library paths.

```bash
cl /I include myapp.c /link /LIBPATH:libs simpleOCCTVP.lib
```

--------------------------------

### Import STL File

Source: https://github.com/secondmouseau/simpleocctvp/blob/main/README.md

Imports a shape from an STL file. Returns an OTShapeRef handle to the imported shape.

```c
ot_import_stl(path);
```

--------------------------------

### Import IGES Robustly (C)

Source: https://github.com/secondmouseau/simpleocctvp/blob/main/docs/reference/c-api.md

Imports an IGES file with automatic healing. Returns a new OTShapeRef or NULL on failure.

```c
OTShapeRef ot_import_iges_robust(const char* path);
```

--------------------------------

### ot_make_solid

Source: https://github.com/secondmouseau/simpleocctvp/blob/main/docs/reference/c-api.md

Attempts to create a solid shape from a given shell. Returns `NULL` if the operation is not possible.

```APIDOC
## ot_make_solid

### Description
Create a solid from a shell. Returns `NULL` if not possible.

### Signature
```c
OTShapeRef ot_make_solid(OTShapeRef shape);
```

### Parameters
- **shape** (OTShapeRef) - The shell shape to convert into a solid.

### Return Value
A new `OTShapeRef` representing the solid shape, or `NULL` if it cannot be created.
```

--------------------------------

### Compile and Link C Code (macOS)

Source: https://github.com/secondmouseau/simpleocctvp/blob/main/docs/guides/getting-started.md

Command to compile and link a C program on macOS, including necessary include and library paths, and setting the runtime search path for the shared library.

```bash
# macOS
cc -o myapp src/main.c -I include -L libs -lsimpleOCCTVP \
   -Wl,-rpath,@executable_path/libs
```

--------------------------------

### Drawer Creation and Destruction

Source: https://github.com/secondmouseau/simpleocctvp/blob/main/docs/reference/c-api.md

Functions to create and destroy an OTDrawerRef. This drawer holds tessellation quality settings.

```c
OTDrawerRef ot_drawer_create(void);
void        ot_drawer_destroy(OTDrawerRef drawer);
```

--------------------------------

### Background Configuration

Source: https://github.com/secondmouseau/simpleocctvp/blob/main/docs/reference/c-api.md

Functions to set the background color or gradient of the viewer.

```APIDOC
## Background Configuration

### `ot_viewer_set_background_color`

Sets a solid background color for the viewer.

**Parameters**
- `viewer` (OTViewerRef) - The viewer to configure.
- `r` (double) - Red component of the color (0.0 to 1.0).
- `g` (double) - Green component of the color (0.0 to 1.0).
- `b` (double) - Blue component of the color (0.0 to 1.0).

### `ot_viewer_set_background_gradient`

Sets a two-color gradient background for the viewer.

**Parameters**
- `viewer` (OTViewerRef) - The viewer to configure.
- `r1` (double) - Red component of the first color.
- `g1` (double) - Green component of the first color.
- `b1` (double) - Blue component of the first color.
- `r2` (double) - Red component of the second color.
- `g2` (double) - Green component of the second color.
- `b2` (double) - Blue component of the second color.
```

--------------------------------

### Shape Material and Emission Functions

Source: https://github.com/secondmouseau/simpleocctvp/blob/main/docs/reference/c-api.md

Allows setting physically based rendering (PBR) materials and emission properties for individual shapes within the viewer.

```c
bool ot_viewer_set_shape_pbr_material(OTViewerRef viewer, int32_t display_id,
        double albedo_r, double albedo_g, double albedo_b,
        double metallic, double roughness);
bool ot_viewer_set_shape_emission(OTViewerRef viewer, int32_t display_id,
        double r, double g, double b, double intensity);
```

--------------------------------

### Export Shape to STEP

Source: https://github.com/secondmouseau/simpleocctvp/blob/main/README.md

Exports a shape to a STEP file. Provide the shape handle and the desired output file path.

```c
ot_export_step(shape, path);
```

--------------------------------

### Save Viewer Image

Source: https://github.com/secondmouseau/simpleocctvp/blob/main/README.md

Renders the viewer's content and saves it directly to an image file. Specify the output path for the image.

```c
ot_viewer_save_image(viewer, path);
```

--------------------------------

### Display Drawer Functions

Source: https://github.com/secondmouseau/simpleocctvp/blob/main/README.md

Functions for creating and configuring display drawers, used for custom tessellation settings.

```APIDOC
## Display Drawer

### `ot_drawer_create()`

**Description**: Creates a new display drawer.

**Returns**: `OTDrawerRef` - A reference to the newly created drawer.

### `ot_drawer_destroy(drawer)`

**Description**: Destroys a display drawer and releases its resources.

**Parameters**:
- `drawer`: The `OTDrawerRef` of the drawer to destroy.

### `ot_drawer_set_deviation_coefficient(drawer, coeff)`

**Description**: Sets the deviation coefficient for tessellation quality.

**Parameters**:
- `drawer`: The `OTDrawerRef` of the drawer.
- `coeff` (float): The deviation coefficient.

### `ot_mesh_shape_with_drawer(shape, drawer)`

**Description**: Meshes a shape using a display drawer with custom tessellation settings.

**Parameters**:
- `shape`: The shape to mesh.
- `drawer`: The `OTDrawerRef` to use for tessellation.
```

--------------------------------

### Import STEP with Healing

Source: https://github.com/secondmouseau/simpleocctvp/blob/main/README.md

Imports a STEP file and attempts to automatically heal any geometric issues. This is useful for repairing potentially problematic STEP files.

```c
ot_import_step_robust(path);
```

--------------------------------

### Make Solid Function Signature

Source: https://github.com/secondmouseau/simpleocctvp/blob/main/docs/reference/c-api.md

Attempts to create a solid shape from a given shell. Returns NULL if the operation is not possible.

```c
OTShapeRef ot_make_solid(OTShapeRef shape);
```

--------------------------------

### Compile and Link C Code (Windows MSVC)

Source: https://github.com/secondmouseau/simpleocctvp/blob/main/docs/guides/getting-started.md

Command to compile and link a C program on Windows using MSVC, specifying include and library paths.

```bash
# Windows (MSVC)
cl /I include src\main.c /link /LIBPATH:libs simpleOCCTVP.lib
```

--------------------------------

### Camera Creation and Destruction

Source: https://github.com/secondmouseau/simpleocctvp/blob/main/docs/reference/c-api.md

Functions to create and destroy standalone camera objects.

```APIDOC
## Camera Creation and Destruction

### Description
Creates a new standalone camera object and destroys an existing one.

### `ot_camera_create`

#### Returns
- `OTCameraRef`: A reference to the newly created camera object.

### `ot_camera_destroy`

#### Parameters
- `camera` (OTCameraRef): The camera object to destroy.
```

--------------------------------

### Lighting Configuration

Source: https://github.com/secondmouseau/simpleocctvp/blob/main/docs/reference/c-api.md

Functions to control lighting, including headlights, directional lights, and ambient light.

```APIDOC
## Lighting Configuration

### `ot_viewer_set_headlight`

Enables or disables the default headlight.

**Parameters**
- `viewer` (OTViewerRef) - The viewer to configure.
- `enabled` (bool) - `true` to enable the headlight, `false` to disable.

### `ot_viewer_add_directional_light`

Adds a directional light source to the scene.

**Parameters**
- `viewer` (OTViewerRef) - The viewer to add the light to.
- `dir_x`, `dir_y`, `dir_z` (double) - The direction vector of the light.
- `r`, `g`, `b` (double) - The color of the light (0.0 to 1.0).

### `ot_viewer_set_ambient_light`

Sets the intensity of the ambient light.

**Parameters**
- `viewer` (OTViewerRef) - The viewer to configure.
- `intensity` (double) - The ambient light intensity.
```

--------------------------------

### Compile and Link C Code (Linux)

Source: https://github.com/secondmouseau/simpleocctvp/blob/main/docs/guides/getting-started.md

Command to compile and link a C program on Linux, specifying include and library paths, and configuring the runtime path for the shared library.

```bash
# Linux
cc -o myapp src/main.c -I include -L libs -lsimpleOCCTVP \
   -Wl,-rpath,'$ORIGIN/libs'
```

--------------------------------

### Standalone Camera API

Source: https://github.com/secondmouseau/simpleocctvp/blob/main/docs/reference/c-api.md

Provides functions for creating, destroying, and configuring a standalone camera. Use these functions to manage camera state independently of any viewer. Matrices are column-major with zero-to-one depth.

```c
OTCameraRef ot_camera_create(void);
void        ot_camera_destroy(OTCameraRef camera);

void ot_camera_set_eye(OTCameraRef camera, double x, double y, double z);
void ot_camera_get_eye(OTCameraRef camera, double* x, double* y, double* z);
void ot_camera_set_center(OTCameraRef camera, double x, double y, double z);
void ot_camera_get_center(OTCameraRef camera, double* x, double* y, double* z);
void ot_camera_set_up(OTCameraRef camera, double x, double y, double z);
void ot_camera_get_up(OTCameraRef camera, double* x, double* y, double* z);
void ot_camera_set_projection_type(OTCameraRef camera, OTProjectionType type);
OTProjectionType ot_camera_get_projection_type(OTCameraRef camera);
void ot_camera_set_fov(OTCameraRef camera, double degrees);
double ot_camera_get_fov(OTCameraRef camera);
void ot_camera_set_scale(OTCameraRef camera, double scale);
double ot_camera_get_scale(OTCameraRef camera);
void ot_camera_set_z_range(OTCameraRef camera, double z_near, double z_far);
void ot_camera_set_aspect(OTCameraRef camera, double aspect);

bool ot_camera_get_projection_matrix(OTCameraRef camera, double* out16);
bool ot_camera_get_view_matrix(OTCameraRef camera, double* out16);
bool ot_camera_project(OTCameraRef camera,
        double world_x, double world_y, double world_z,
        double* out_x, double* out_y, double* out_z);
bool ot_camera_unproject(OTCameraRef camera,
        double ndc_x, double ndc_y, double ndc_z,
        double* out_x, double* out_y, double* out_z);
bool ot_camera_fit_bbox(OTCameraRef camera,
        double xmin, double ymin, double zmin,
        double xmax, double ymax, double zmax);
```

--------------------------------

### Import IGES File

Source: https://github.com/secondmouseau/simpleocctvp/blob/main/README.md

Imports a shape from an IGES file. Provide the file path as an argument.

```c
ot_import_iges(path);
```

--------------------------------

### Display Drawer Functions

Source: https://github.com/secondmouseau/simpleocctvp/blob/main/docs/reference/c-api.md

Functions for creating, destroying, and configuring display drawers. These drawers hold tessellation-quality settings for mesh extraction.

```APIDOC
## Display Drawer API

### Create Drawer

```c
OTDrawerRef ot_drawer_create(void);
```

Creates a new display drawer.

### Destroy Drawer

```c
void ot_drawer_destroy(OTDrawerRef drawer);
```

Destroys the specified display drawer.

### Set Deviation Coefficient

```c
void ot_drawer_set_deviation_coefficient(OTDrawerRef drawer, double coeff);
```

Sets the deviation coefficient for the drawer.

### Get Deviation Coefficient

```c
double ot_drawer_get_deviation_coefficient(OTDrawerRef drawer);
```

Gets the current deviation coefficient of the drawer.

### Set Deviation Angle

```c
void ot_drawer_set_deviation_angle(OTDrawerRef drawer, double radians);
```

Sets the deviation angle in radians for the drawer.

### Get Deviation Angle

```c
double ot_drawer_get_deviation_angle(OTDrawerRef drawer);
```

Gets the current deviation angle of the drawer.

### Set Max Deviation

```c
void ot_drawer_set_max_deviation(OTDrawerRef drawer, double deviation);
```

Sets the maximum deviation allowed for the drawer.

### Get Max Deviation

```c
double ot_drawer_get_max_deviation(OTDrawerRef drawer);
```

Gets the current maximum deviation of the drawer.

### Enable Face Boundary Draw

```c
void ot_drawer_set_face_boundary_draw(OTDrawerRef drawer, bool enabled);
```

Enables or disables drawing of face boundaries.

### Get Face Boundary Draw Status

```c
bool ot_drawer_get_face_boundary_draw(OTDrawerRef drawer);
```

Gets the current status of face boundary drawing.

### Mesh Shape with Drawer

```c
OTMeshData ot_mesh_shape_with_drawer(OTShapeRef shape, OTDrawerRef drawer);
```

Generates mesh data for a shape using the specified drawer settings. The returned data is caller-owned and must be freed with `ot_mesh_free`.

### Edge Mesh Shape with Drawer

```c
OTEdgeMeshData ot_edge_mesh_shape_with_drawer(OTShapeRef shape, OTDrawerRef drawer);
```

Generates edge mesh data for a shape using the specified drawer settings. The returned data is caller-owned and must be freed with `ot_edge_mesh_free`.
```

--------------------------------

### Rendering Output

Source: https://github.com/secondmouseau/simpleocctvp/blob/main/docs/reference/c-api.md

Functions to render the scene to a buffer or save it as an image file.

```APIDOC
## Rendering Output

### `ot_viewer_render`

Renders the scene and returns a pointer to the pixel data.

**Parameters**
- `viewer` (OTViewerRef) - The viewer to render.
- `out_width` (int32_t*) - Pointer to store the width of the rendered image.
- `out_height` (int32_t*) - Pointer to store the height of the rendered image.
- `out_size` (int32_t*) - Pointer to store the size of the pixel data buffer in bytes.

**Returns**
- `const uint8_t*` - A pointer to the RGBA pixel data (bottom-to-top order). The pointer is owned by the viewer and is valid only until the next render call or viewer destruction.

### `ot_viewer_render_to_buffer`

Renders the scene into a caller-provided buffer.

**Parameters**
- `viewer` (OTViewerRef) - The viewer to render.
- `buffer` (uint8_t*) - The buffer to render the pixels into.
- `buffer_size` (int32_t) - The size of the provided buffer in bytes.

**Returns**
- `bool` - `true` if rendering to the buffer was successful, `false` otherwise. The pixel data is in top-to-bottom order.

### `ot_viewer_save_image`

Renders the scene and saves it to an image file.

**Parameters**
- `viewer` (OTViewerRef) - The viewer to render.
- `path` (const char*) - The path to the output image file. The format is determined by the file extension (e.g., `.bmp`, `.png`).

**Returns**
- `bool` - `true` if the image was saved successfully, `false` otherwise.
```

--------------------------------

### Set Viewer Background Color

Source: https://github.com/secondmouseau/simpleocctvp/blob/main/README.md

Sets a solid color as the background for the viewer. Specify the RGB color components (0.0 to 1.0).

```c
ot_viewer_set_background_color(viewer, r, g, b);
```